Military free fall training injuries.

Military free fall or HALO (high altitude-low opening) is a distinct form of tactical parachuting used by the elite forces of the U.S. military. This study was undertaken to examine the type, location, and mechanism of injuries sustained by the military HALO parachutist during training. A retrospective study identified 134 parachutists with 141 injuries attributed to HALO training. The most common injuries were fractures (35.5%) and sprains/strains (34.7%). The sites most commonly injured were the lower extremities (52.5%), upper extremities (19.8%), and spine (14.9%). Landing was the most frequently encountered mechanism of injury (61.2%), followed by ground free fall simulation (wind tunnel training) and canopy deployment. Night jumping, wearing of combat equipment, and use of oxygen during high-altitude jumps were all variables that contributed to injury. The military free fall parachutist is predisposed to a wide array of musculoskeletal injuries at different training phases.